Diabetes mellitus patients require administration of varying amounts of insulin throughout the day to control their blood glucose levels. Ambulatory portable insulin infusion pumps can be used as superior alternatives to multiple daily syringe injections of insulin. However, although these devices represent an improvement over multiple daily injections, they nevertheless all suffer from several drawbacks. One drawback is the large size and weight of the devices, caused by the configuration and the relatively large size of the driving mechanism and syringe. These relatively bulky devices have to be regularly carried in a patient's pocket or attached to his/her belt.